And now I'm pretty much the only person on the forum who didn't "get" KoDP. I mean, I've played it and its fairly fun, but I can't figure out what decisions are going to be good or bad, to the point that to me it feels like I'm not so much playing a game as a random number generator.
Is this hero quest gonna work? Lets ask the magic 8 ball! Nope, no it is not. And neither is anything else you try because you don't know the square root of an antelope.
Also the whole "can never fully defeat an enemy tribe" thing is pretty sucky. Makes war tribes feel pointless imo.
So in general when making decisions, you need to act like your ancestors. It means acting according to the answers you gave at the very start of the game, and sometimes based on past decisions you made during gameplay. If that is not applicable to the situation, you then need to consider what an orlanthi would do. Having a trickster is also incredible since they are great ways to tell what needs to be done; that is because if everyone and the trickster agree on something it's the right choice, and if only the trickster suggests something it is then the wrong choice (there are a few exceptions, but they are pretty obvious).
For questing, higher magic is good, as is having allies send helpers to you. The magic resource is literally your luck, so having high magic is just good no matter what. High stats on the quester is good, as is investing in the sacred time in the quest category. And, of course, only go for alt-history in the quest if you somehow fail the regular course (I see it happen more often on Elmal's quest) or are feeling bold. Some quests are harder than others. Orlanth and Aroka, Elmal's, and particularly Uralda's are pretty brutal. Making of the Storm Tribe is probably the easiest.
On war: orlanthi go to war to raid and weaken, not to exterminate. That said, setting your tribe as a war tribe is a terrible idea. You want peaceful or balanced based on how often you want to raid.
EDIT: All that said, sometimes RNGesus just hates you and then you are screwed.